Debarking and debranching apparatus

ABSTRACT

A rotary debarker-debrancher consists of apparatus having two coaxially positioned rings defining a path through the center thereof for a bole to travel for processing. The debarkingdebranching tool arms have each of their ends pivotally mounted to a separate ring, both rings being rotated by power means in the same direction. The apparatus includes means for altering the circumferential position of one ring with respect to the other during rotation with the result being that the tools are pivoted inwardly or outwardly into or out of engagement with the circumferential surface of the tree. The tools are mounted on plates which overlap in an iris pattern to inhibit debris from entering the apparatus. Further, the tools are rotated in a direction to provide a lead cutting action to remove bark and branches from the bole and therefore throw it outwardly from the apparatus.

United States Patent McColl DEBARKING AND DEBRANCHING APPARATUS [72]Inventor: Bruce John McColl, Whitby, On-

tario, Canada [73] Assignee: Owens-Illinois, Inc.

[22] Filed: Oct. 7, 1970 [2]] Appl. No.: 78,764

Related US. Application Data [63] Continuation-impart of Ser. No.572,530, Aug.

15, 1966, Pat. No. 3,533,458.

52 us. 01 ..144/2 z, 144/208 E 51 Int. Cl. ..A01g 23/02 [58] Field ofSearch ..82/59, 60, 67, 68; 144/2 2,

Brundell et a1 144/2 Z 1 Dec. 5, 1972 FOREIGN PATENTS OR APPLICATIONS31,052 6/1911 Sweden ..144/208 E 90,087 9/1957 Norway ..144/208 E119,397 10/ 1958 U.S.S.R ..144/2 2 Primary Examiner-Gerald A. DostAttorney-Beveridge & De Grandi 5 7] ABSTRACT A rotarydebarker-debrancher consists of apparatus having two coaxiallypositioned rings defining a path through the center thereof for a boleto travel for processing. The debarking-debranching tool arms have eachof their ends pivotally mounted to a separate ring, both rings beingrotated by power means in the same direction. The apparatus includesmeans for altering the circumferential position of one ring with respectto the other during rotation with the result being that thetools arepivoted inwardly or outwardly into or out of engagement with thecircumferential surface of the tree. The tools are mounted on plateswhich overlap in an iris pattern to inhibit debris to remove bark andbranches from the bole and therefore throw it outwardly from theapparatus.

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ATTORNEYS DEBARKING AND DEBRANCHING APPARATUS This application is aContinuation-in-Part of my United States Patent application Ser. No.572,530 filed Aug. 15, 1966, now US. Pat. No. 3,533,458 and whichdiscloses a mobile tree processing factory for pulp mill raw material towhich the present invention is ideally suited. 1

This invention relates to the tree processing aspect of forestharvesting and in particular to the processing operations of treedebranching, debarking or a combination thereof.

The term bole as used throughout this application defines the trunk of atree which has been severed from its stump and in particular thatportion of the tree extending from the butt end to its merchantable topdiameter, excluding branches and bark.

There are numerous single purpose devices now being used for theoperations of debarking and debranching trees either before or afterremoval from the stump. However, a considerable gap remains between thisstate of the art hardware and an optimum device which willeffectively-remove both bark and branches froma tree bole under a broadrange of operating conditions and at the same time permit theintegration of concurrent handling and subsequent operations such aschipping. Thepresent invention is intended to provide a basic apparatuswhich will remove bark andbranches from a tree so that its bole may befurther processed into pulp mill raw material such as chips; and withoutthe possibility of bark contamination that now exists. The removal ofbark and branches is preferably, though not necessarily, effected withthe bole in a generally vertical position.

The known means of effective mechanical debarking depends upon thecambium shear principle. A shortcoming of debarkers of this type is thatdebarking tool configurations are based on a trail cutting" action tocrush the cambium layer, fragment the bark and tear it away from thehole. However, this action causes the bark to be drawn into the area oftool operation on the hole surface causing a clogging of the tools andthe retention of debris at the processing point. Conversely, the toolsof the present invention provide for a leadcutting action to improve theeffectiveness of tool action at the bole surface; and to throw the barkoutwardly or away from the bole.

Additionally the tool arm structure of the debarker disclosed in thisapplication is arranged in an iris pattern for effective closure aroundthe bole so that, when used in a prefered vertical orientation, bark isinhibited from dropping down into the apparatus.

The processing operation of debranching by mechanical means requires theapplication of appreciable power to cut, break, or otherwise removebranches at their juncture with the bole of a tree. These means rangefrom:

a. drawing a tree of large mass, at relatively low speed and high force,through stationary, variableopening devices having knife-like elementsat their 1 leading edge to;

b. moving a fixed or variable opening device of relatively low mass athigher speeds and lower force along the length of a stationary tree; or

c. by applying high rotational speed cutting and/or impacting tools,such as cutters, hammers, chain flails etc., to the hole surface,thenmoving either the tools or the tree so that the circumference andlength of the hole may be covered by the debranching means. Debranchingof poor quality and/or unacceptable wood loss are well known productproblems. High power consumption and an inability to effectivelyintegrate associated handling with major processing operations havelimited the efficiency of debranching as a part of the overallproduction operation.

The apparatus of this invention provides a debranching device whichutilizes the energy of a rotating debrancher-debark'er head .to shearbranches from the bole. Following initial start-up of the head, neitherthe mass of the tree nor themass of the head need to be accelerated toeffect the debranching operation, this operation being carried out inconjunction with debarking in such a way or to approach a constant poweroperating condition for processing.

The apparatus of this invention also provides a debranching-debarkingdevice which exhibits a relatively short linear length in contact withthe bole surface on whichit will operate. The reduction of the linearlength required for the processor increases the tool effectiveness on acurved bole while reducing the length and weight of the processor head.Additionally, the invention discloses simplicity in tool design toprovide reliability and ease of replacement.

Additional features of this invention include a debranching-debarkingdevice in which the tools maintain a constant circumferential operationon a bole of a tree fed into the apparatus; a mechanical feedback as thetool control means thereby rendering it responsive to variations in bolediameter and surface irregularities; and freedom to float thedebranching-debarking tools in a plane normal to bole travel so as toaccommodate variations in the axis of the tree bole.

The above-mentioned and other features will become apparent from thefollowing description and the accompanying drawings in which:

FIG. 1 is an overall perspective view of a tree processing machine asdisclosed in my aforesaid copending application Ser. No. 572,530, themachine embodying the present invention;

FIG. 2 is a sectional view taken through a primary arm of the machine inFIG. 1 showing the disposition of one embodiment of adebranching-debarking means in that arm;

FIG. 3 is a diagrammatic view of the debranching-debarking mechanismshown in FIG. 2 and illustrating the relationship to the various treeprocessing mechanisms as the butt end of the bole is being introduced tothe apparatus;

,FIG. 4 is a view similar to FIG. 3 showing the relationship of themechanism to the same bole but towards the end of the processingoperation;

FIG. 5 is a sectional view taken along the lines 55 of FIG. 2;

FIG. 6 is a side elevation view of a second embodiment of thedebrancher-debarker and its associated rotating mechanisms;

FIG. 7 is a front elevation of the device of FIG. 6;

FIG. 8 is an enlarged, more detailed frontal view of the mechanism andshows one operative position of the tool arms on a bole;

FIG. 9 is a plan view of the basic tool arm;

FlG. 10 is a plan view of a debarker blade as shown on the tool arm; 7

FIG. 11 is a partial side view of the blade arrangement of FIG. 10',

FIG. 12 is an elevation view partly in section of one tool arm and itsassociated mechanism, showing positions thereof during a debranching anddebarking operation; and

FIG. 13 is a sectional view taken along lines 13-13 of FIG. 6.

The present invention is preferably applicable on a mobile platform suchas a tree processing apparatus operable in the field. FIG. 1 is a viewof one such processing machine, the subject of my correspondingapplication Ser. No. 572,530. It will be seen from FIG. 1 that thismachine 1 includes a pair of primary arms 2 one pivotally secured toeither side of the machine 1, each primary arm 2 carrying adebarker-debrancher mechanism 3 arranged in vertical orientation. Asecondary arm 4 is movably secured to the primary arm 2 and secondaryarm 4 carries a tree grasping, severing, and secondary feed mechanismgenerally indicated at 5. The latter includes impact shears 6 adapted tosever a tree from its stump whereupon the grasping mechanism ispositioned as of FIG. 1 shown on the right hand primary arm on themachine to feed the severed tree into the debarking-debranchingmechanism 3 where the tree will be stripped of its bark and branchesand, in accordance with the disclosure of application Ser. No. 572,530,reduced to chips by means of a chipping mechanism in the lower end ofthe primary arm 2 so that the chips will serve as a suitable rawmaterial for a pulp manufacturing operation. As will be described later,the chips are subsequently transferred from the area of the primary arm2 into the storage means 7 carried by the rear portion of the vehicle 1.

In accordance with the embodiment shown in FIGS. 1 through 5 inclusive,the debarking and debranching apparatus 3 embodies three debarking anddebranching tools 10 which are carried by a rotating plate 12 whichrotates the tools in a lead cutting action on the bark in the directionof arrow C in FIG. 1. In a full open position, tools 10 may be displacedso that their radially inner ends spread apart to allow the butt end ofa tree to be introduced, the diameter of this maximum opening beingapproximately 18 inches for typical pulpwood operations. In the fullclosed position, tools 10 run upon the surface of a merchantable treetop diameter of approximately 4 inches. The action of the radially innerends of the tools 10 upon the bark of a bole removes the bark whichenters the hollow body of each tool 10 and is flung outwardly bycentrifugal force to distribute the bark over the ground in the stumparea. This action of the tools 10 is shown in FIGS. 3 and 4.

Turning now to FIGS. 2 and 5, the debarking and debranching mechanism 3is seen housed within a slight upward enlargement of the primary arm 2which occurs with a sloping wall 14. The entire debarkingdebranchingmechanism is carried by a base plate 16 which is slidably mounted inways carried by the structural members of primary arm 2 in a mannerwhich will be more clearly recognized from a consideration of FIG. 5which is a section view taken along along line 5-5 of FIG. 2. In FIG. 5plate 16 is shown as being mounted for sliding movement at each edge inways 18 carried by structural frame members 20 of primary arm 2. Thebase plate 16 is provided with a central aperture 22 about whichandradially therefrom is an annular spigot 24. Mounted on spigot 24 byinner bearings 26 is a ring 28 having a first axial portion 30 and asecond radial portion 32 extending radially outwardly and overlappingthe spigot 24 and being formed with a peripheral chain sprocketconfiguration at 34. Mounted on outer bearing 36 is a second annularring 38 which, as well, is formed with a peripheral chain sprocketconfiguration 40. Motors 42 and 44 are provided, mounted upon base plate16 and movable or slidable therewith. Motor 42 is provided with adriving sprocket 46 on its shaft and about driving sprocket 46 isentrained a chain 48 which is also entrained about the sprocketconfiguration 34 of ring 28. Motor 44 carries sprocket 50 on its shaftdriving through chain 52 to ring 38 by means of the sprocketconfirguration 40 formed on its periphery.

The radial flange 32 of ring 28 carries vertically extending pins atthree equiangularly spaced points about the periphery of opening 22 inbase plate 16 which is, of course, axially aligned with opening 56 inring 28 and which, together, define the opening through which the bolewillenter the apparatus and pass therethrough. Ring 38 is also providedwith pins, these bearing reference numeral 58 and which pass througharcuate slots 60 formed in the radial flange 32 of ring 28. The upperends of pins 54 and 58 can be seen in FIG. 1 mounting the debarking anddebranching tools 10, one of which is also shown in dotted lines in FIG.5.

It will be apparent that since pins 58 pass through slots 60 in ring 28,it is necessary that motors 42 and 44, for the most part, run insynchronism and that ring 28 is rotated at exactly the same speed asring 38. In this way, the tools 10 will be caused to orbit the axis ofapertures 22 and S6 with their inner ends defining a circle concentricwith that axis. If ring 28 were, as seen in FIG. 1, to be advancedslightly ahead of ring38, then pin 54 would be displaced angularlyrelative to pin 58 with the result that the relative position of tool 10would change, the inner end of the tool moving radially outwardly inorder to define a larger circle about the axis of openings 22 and 56.Conversely, if ring 38 were to be advanced relative to ring 28 or, inother words, rotated slightly faster for a very brief moment, then pin58 would catch up with pin 54 thereby changing the angular position oftool 10 so as to move its free end radially inwardly to define a smallercircle in its orbit about the common axis of openings 22 and 56.Accordingly, the opening and closing of tools 10 so as to, in the firstplace, provide a wide open entry port for the initial entry of the buttend of a hole and to subsequently close down upon the bole to remove itsbark and to follow the changing diameter of that tree as it is fed intothe machine from its largest diameter adjacent its butt to its smallestdiameter adjacent its top can be achieved by simply selectivelycontrolling the relative speed of rotation of motors 42 and 44 over anarrow range and over a very brief time interval so as to provide a veryprecise, accurate and immediately responsive control of the debarkingtools 10. Numerous advantages flow from this construction, not the leastof nan:

which is that the entire rotating mass can be dynamically balanced andutilized to stabilize the debarkingdebranching power requirement.

Formed within the base member 16 and surrounding the central opening 22is an annular air gallery 62 from which there extends upwardly slopingair jets 64 adapted to direct an upwardly flowing air blast through thealigned openings 22 and 56 for the purpose of blasting upwardly anyloose bark or other debris which forms during the debarking operation.As was described above, the majority of the bark will enter the hollowtools and be discharged centrifugally in a radial direction. Theprovision of plate 12 also blocks off a large portion of the areaadjacent the bole to prevent bark from entering the interior of arm 2.However, a certain amount of bark would fall downwardly through openings56 and 22 into the interior of the primary arm 2 and would, in timeaccumulate to an objectionable extent. Accordingly, in addition to plate12 the air blast is provided in order to reduce, as much as possible,the entry of bark and debris within the primary arm 2. The air gallery62 will be supplied in a known manner (not shown) with compressedair'fromair lead 63 which is illustrated in FIG. 3.

In addition to performing the debarking function, the radially innerends of the tools 10 are provided with upwardly extending knives 66which orbit about the same axis as do the debarking portions of thetools. The knives 66 are provided with cutting edges directed in thedirection of rotation and the knives will serve to sever from the treetrunk any projecting branches and, to some extent, to smooth down bumps,knobs and other sharp projections which might interfere with laterhandling of the bole within the processing apparatus. Reference will behad later to FIG. 4 in greater detail but in this figure the function ofthe debranching knives can be very readily seen.

Immediately below the debarking-debranching apparatus is a primary feedand guide apparatus essentially comprising guide idler rollers 68,powdered feed rollers 70, feed roller driving motor 72, adjusting motor74 and supporting framework securely fixed within the structuralcomponents of the primary arm 2.

The guide and feed apparatus has been illustrated more fully in mycopending application Ser. No. 572,530. It is sufficient for thisapplication to consider FIGS. 2, 3 and 4 which show that a second orlower pair of guide rollers 68 are vertically aligned with the upper setof rollers 68 and arranged with their axis forming an angle of 90 to oneanother.

LOcated between the upper set and the lower set of rollers 68 is arearwardly extending yoke comprising a transverse forward member and apair of rearwardly extending arms 75 which constitute ways within whichmay slide mounting flanges of the support mechanism carrying the poweredfeed rollers 70. Rollers 70 are driven by motor 72 running through agear reduction box, driving sprockets and drive chains, not shown, asdescribed in application Ser. No. 572,5 30.

The position of feed roller 70 relative to the 90 V formed by idlerrollers 68 is determined by the operation of motor 74 which is housedwithin a member of the rearwardly extending yoke. As described inapplication Ser. No. 572,530 the motor 74 is of the doubleshaft typedriving into a bevel gear box to rotate lead screws engaged with captivenuts so that operating the motor 74 in one direction will advance thecarriage carrying powered feed rollers towards the idler rollers 68 soas to engage a bole positioned therebetween and reverse operation of themotor will withdraw the carriage from such engagement.

It will be noted that a hole engaging orentering the guide and feedapparatus disclosed in FIGS. 2, 3 or 4 will be engaged about two radialplanes spaced along its length, and at each of these points, will becontacted at three planes spaced about its circumference. This providesfor an extremely stable support and guide for the bole and also providesfor simple and positive engagement with the bole by the powered feedrollers 70 which rotate to feed the hole downwardly with respect to FIG.2.

As disclosed in detail in application Ser. No. 572,5 30 the secondaryarm 4 (FIG. 1) initially feeds the butt end, of a bole into thedebranching and debarking mechanism 3 which at that moment is in a wideopen position. Then control of the speed of motors 42 and 44 will causethe debranching and debarking tools 10 to close down upon the bolesurface, engage it, remove the bark, and, if any, thebranches thereon.Continued downward movement will cause the butt of the hole, havingpassed through the debarking and debranching mechanism and having hadits bark removed, to begin to enter the guide and feed mechanismillustrated in FIGS. 3 and 4.

Motor 74 will advance the carriage containing the powered drive rollers70 until these rollers are firmly in engagement with the surface of thebole and the support for the bole and the feed downwardly thereof willbe assumed by the guide and feed mechanism illustrated in FIGS. 3 and 4.

As shown in FIGS. 2, 3 and 4, primary arm 2 includes a chipping wheel 76for further processing the debarked and debranched bole. The chipper 76is a dual truncated cone type chipper having a deep V-shaped groove inits radial periphery, the sides of this groove being provided withchipping teeth or blades which are schematicallyillustrated at 78 inFIG. 2. The chipping wheel 76 is driven through a gear 80 keyed to itsmounting shaft 82, the gear 80 being engaged by worm 84 driven by driveshaft 86 which, in turn, is driven through a gear box and motor 88 asshown.

As the bole is driven downwardly against the chipping surfaces ofchipping wheel 76, the bole will be reduced to chips which, initially bycentrifugal force, will be flung in the direction of arrow D into ductor conduit 92. Additional kinetic energy will be imparted to the chipsat approximately point 93 by air jets supplied with pressurized air fromair line 63 to cause the chips to pass upwardly and rearwardly andrearwardly along duct 92 to eventually be blown into the storage means7, FIG. 1.

Referring to FIG. 1, a typical southern softwood tree can be seen ascomprising a branch crown and a relatively straight bole. As the bole isfed downwardly into the chipping wheel 76 by means of the feed rollers70 acting against idler rollers 68, the bole diameter will continuallyreduce and feed rollers 70 will continually be advanced towards idlerrollers 68 by the operation of motor 74. At the same time, debarking anddebranching tools 10, under the control of motors 42 and 44 will befollowing the reducing diameter of the hole so as to continuouslyperform their operation upon it.

In this embodiment both the debarking and debranching mechanism 3 andthe guide and feed roller mechanism generally shown in FIGS. 3 and 4 areable to close down so as to bear against and act upon a bole having aminimum diameter of approximately 4 inches. The characteristic of thekind of tree encountered in southern pulpwood operations is such thatthe tree hole has, as a general rule, more or less disappeared andbecome indistinguishable from the laterally extending branches by thetime the tree trunk diameter has been reduced to something of the orderof the 4 inch minimum size. The debranching knives 66 will, as the bolediameter reduces, ultimately orbit about a 4 inch diameter circle andwill server all of these branches and, at some point, when the bole hasceased to exist as such, the debranching knives 66 will finally severall of the remaining tree so that the debarking knives then orbiting ina 4 inch circle will no longer contain any material within that circleand, in this way, the top of the bole is simply disposed of by allowingthe severed branches to be discharged radially outwardly of thedebarking and debranching mechanism to fall upon the ground below theprimary arm 2. i I

In those instances where there is a bole extending in a more or lessstraight line so as to lie within the minimum circle orbited by thedebranching knives 66, this small hole portion will, under the pullinginfluence of the chipper, simply be drawn into the chipping wheel 76 ata very rapid rate since its feed will no longer be under the control ofthe feed rollers 70, which, as stated above, cannot act upon trees ofmuch less than 4 inches in diameter.

In this event, if a bole of less than 4 inches in diameter is passed tothe chipping wheel, the chipping wheel would then produce chips of aquality unsuitable for pulp production since the bark will not have beenremoved due to the fact that the debarking apparatus will not act upontrees of that diameter.

To overcome this problem the duct 92 is provided with a valve 94 which,under normal conditions occupies the solid line position shown in FIGS.3 and 4. When, however, the debarking and debranching tools 10 haveclosed down to their minimum extent and are, therefore, incapable ofremoving bark from boles of smaller diameter, actuator 96 (FIG. 2) willbe energized so as to move the valve 94 from its solid line position toits dotted line position as shown, thereby opening a port in duct 92 soas to allow those chips including bark from small diameter tree portionsto be ejected onto the ground, thereby avoiding contamination of thechips which are delivered to the duct 92 and, thence to the chip storagemeans 7.

Having described in some detail the apparatus associated with primaryarm 2, it might be convenient now to refer to FIGS. 3 and 4 in which thevarious functions which-have so far been described are illustrated in amore or less schematic form. FIG. 3 illustrates the introduction of thebutt end of a hole T into the apparatus and shows the initial debarkingof the butt and the radial discharge of thebark through the hollowdebarking tools. In the position shown in FIG. 3, the hole is stillunder the control of, and being fed by the secondary feed system of arm4 although, as can be seen, the carriage containing the powered feedrollers is being advanced in the direction of the arrow F in order toengage the surface of the bole when the butt thereof has passed the axisof rotation of the lower idler rollers 68. The chipping wheel 76 iscontinuously rotating and is ready to begin the chipping operation onthe butt of the bole as soon as it is engaged thereby.

FIG. 4 shows the same bole at a later point in the processing cycle. Thesecondary feed system of arm 4 has been released from the bole andoperating on its tree gathering cycle. Feed rollers are now engaged withthe surface of the bole, controlling its position and driving itdownwardly into the chipping wheel 76 which is discharging chips alongduct 92 with the assistance of an air jet entering through port 93. Feedrollers 70 control the feed rate of the hole to the chipper 76 tomaintain the desired chip quality. The debarking tools 10 are stillremoving bark from the bole and, at the same time, the debranchingknives 66 have now encountered branches towards the top of the bole andare removing them before that portion of treeenters the debarkingmechanism.

It should also be noted that rollers 70, as can best be seen inschematic drawing FIG.4 are mounted for a rocking motion about an axisindicated at' 70A in FIG. 4. In this way, the feed rollers 70 canaccommodate such localized disturbances as may be encountered upon bolesbeing fed through the apparatus.

The second embodiment of this invention is illustrated in FIGS. 6through 13 inclusive and referring firstly to FIG. 8, the debranchingand debarking apparatus is illustrated generally at and utilizes threedebranching and debarking tools 102 which are supported by rotatableouter and inner rings 103 and 104 respectively. The rotation of theapparatus is effected counter clockwise in the FIG. 8 view whereby thetools 102 orbit a circumferential path about the center of the apparatus100 which, in FIG. 8, is occupied by a bole T.

In a preferred embodiment of the invention as shown in the fullyassembled drawings of FIGS. 6 and 7, the outer and inner rings 103andl04 (FIG. 8) are supported for rotation in a casing and are rotatedby suitable drive means, not shown, through a rotary actuator 112 whichprovides and governs relative rota tional positional changes between therings 103 and 104 in a manner and for a purpose to be subsequentlydescribed. Rings 103 and 104 correspond to rings 28 and 30 of FIG. 5 andthe actuator 112 of the present embodiment fulfils the function of thespeed differential effected to the rings 28 and 30 in FIG. 5 by theirmotors 42 and 44, that is, the circumferential position of one ring isaltered with respect to the other. Additionally, the apparatus 100 isalso provided with sufficient float freedom as is the first embodiment,normal from the longitudinal axis of the hole T to compensate for crooksand other axial irregularities normally encountered in the bole of atree.

FIGS. 9 through 12 illustrate the debarkingdebranching tool 102 indetail, FIG. 8 providing a frontal view of the assembled apparatus100exclusive of the casing 110 and the actuator 112, with FIG. 12showing in side-elevation one tool 102 in an operative position.Referring to FIGS. 9 and 12, each tool 102 comprises a tool support arm114 with two stepped lower plates, 116, 118 and an upper plate 120secured to andspaced from plate 118 by a rectangular pivot block 122.Plate 116 provides a leading end 124 to the complete tool 102 by meansof an elongated slot 126 pivotally securing that end to the innerrotatable ring 104 by a pivot pin 128 (FIG. 8). The other or trailingend 130 of the tool 102 is pivotally mounted to the outer rotatable ring103 of the apparatus by a swivel pin 132 passing through block 122 asshown in FIGS. 8 and 12.

Plate 118, adjacent its connection with plate 1 16, includes a guideshoe 134 adapted to ride on the surface of the bole just below thedebarking members. Upper plate 120 carries a debranching knife 136 byway of a holder 138 secured to a terminal end of the plate 120 via studs140, see FIG. 8. In this manner, debranching knives 136 are readilyreplaceable.

The plates 118 and 120 of the support arm 114 are align bored at 142,(FIGS. 9 and 12), to receive a pin 144 (FIGS. 8 and 11) on which thetool assembly is mounted. Pin 144 is anchored in plate 120 by pin 145.As shown in FIGS. and 11, pin 144 pivotally supports a plurality offingers 146 each of which is separated from an adjacent finger by aknuckle spacer 148. It will be noted from FIG. 10 that knuckle spacer148 has a planar side portion 150 abutting against a like surface of thepivot block 122.

The fingers 146 and knuckle 148 may move relative to one another but aremaintained generally in the FIG. 10 position by springs 152 coiled aboutconnecting rods 154. A rotatable pin 156 having a flattened spring seatpasses through the outer terminal ends 158 of knuckle 148 and pin 156slidably receives one end of each connecting rod 154 as illustrated. Astop pin 155 in the terminal end of the rods 154, prevents the rod frombeing pulled through pin 156 under the pressure of the spring 152. Theother ends of rods 154 are each pivotally mounted to the free ends ofthe fingers 146 by yokes 160 and pins 162.

Spacer knuckle 148 is drilled at 149 (FIG. 10) to receive a pin 164mounting one end of a link 166 (FIGS. 8 and 12) which, together withvertical rod 168, secure the knuckle 148 to an arm 169 mounted fast onthe upper end of the pivot 132 which mounts. the tool assembly and is,itself, mounted on ring 103 of the main assembly. However, knuckle 148and the associate structure of fingers 146 are limited in relativemovement by the lever arm 166 which is slotted as shown by the brokenlines 167 in FIG. 8, at its connection to the pin 164.

Lastly, each finger 146 carries, at its outer end thereof, an arcuateshaped debarking blade 170. The number of fingers 146 and blades 170 tobe used is dependent on the type of tree being processed, the feed rateof the bole passing through the apparatus and other factors. However,for the purpose of this application three fingers and blades are shownas in FIG. 12.

There are several observations to be made at this point with respect tothe assembly drawing of FIG. 8. First, the tool support assemblies 102,102a and 1021) have a base structure of stepped plates 116 and 118(FIGS. 9 and 12) that provides circumferential overlay of plates 116 oftool 102 by plate 118 of adjacent tool 1020 for all positions of 102 and102a from full open to full close. Similarly, plate .116 of 102a isoverlayed by plate 118 of 10212 and plate 116 of 102b by plate 118 of102 thereby to form an iris that substantially closes the whole surfaceof the apparatus 100. When the apparatus is used in a verticalenvironment such as the processing machine of FIG. 1, this irisconstruction inhibits bark from dropping down into the lower end ofprimary arm 2. The only areas not closed are those small areas indicatedat C in FIG. 8. Such areas may be maintained free of debris by theprovision of upwardly directed air jets of the type shown in FIG. 5.

Secondly, the debranching knives 136 and the debarking tools 170 rotateor orbit counter clockwise about the bole T to provide a lead cuttingaction as opposed to the trail cutting action of prior art devices toremove limbs and bark from the bole of a tree. The lead cutting actionand tool shape accelerates loose material outwardly from the tools 102and apparatus thereby removing branches and bark from the area ofopenings C to further inhibit the entrance of debris into the confinesof the apparatus. Thirdly, guide shoes 134 control the position of thedelimbing knives 136 on the bole surface and provide a basic mechanicalfeedback control for those knives and for the debarking tool assembly.It will be observed from FIGS. 8 and 9 that the guide shoes 134 eachhave an arcuate shape whichv conforms them collectively to a largecircumferential surface of the bole as shown in FIG. 8. This largecircumferential area in contact with the freshly debarked surface of thebole minimizes crushing; is self lubricating; and provides a highlyresponsive delimbing tool control means.

Fourth, it will be observed from-FIGS. 8, l0 and 12 that the operatingtips of debarking blades are maintained in constant contact with thesurface of the bole under pressure of springs 152 acting to press theblade 170 and fingers 146 away from the knuckles 148. The provision ofthe coiled spring 152 on the rod 154 which is slidably positioned in thepin 1S6, ensures that the debarking blades 170 float on the surface ofthe bole to remove the bark therefrom. The amount of float is limited bythe movement of the pin 164 in the slot 167 of the arm 166 as shown inFIGS. 9 and 11, such limitation being required to restrain the inwardmovement of debarking tools 170 when a hole is not present in theapparatus.

In the earlier described embodiment, the debarking and debranching rings28 and 38 were rotated by motors 42 and 44 as shown in FIG. 5. Bychanging the relative rotational speed of one motor with respect toanother over a narrow range and for a very brief time interval, thedebarking tools 10 which were attached to those rings could beaccurately adjusted so as to act on a bole being fed through theapparatus 1. Each tool was pivoted about two pivot points i.e., the pins54 and 58 projecting upwardly from the rings 28 and 38. By altering thecircumferential position of the rings with respect to one another, thetools 10 pivoted on those pins were caused to move their cutting endscloser or farther away from the center of the apparatus 1.

A fifth observation therefore with respect to the present embodimentrelates to the mounting of the tools 102 on the outer and inner rings103 and 104 and the differences and improvements of the present mountingover the earlier embodiment. It will be noted from FIG. 8 that each tool102 extends almost completely across the apparatus 100 in adiametrically opposed arcuate path and the spacings of the pivot pointsare almost twice as great as those in the earlier embodiment. Thus, oneend of tool 102 is pivoted about pin 132 while its other forward end 124is pivoted about the pin 128 which extends upwardly from the ring 104through the slot 126. It will be appreciated that outer and inner rings103 and 104 rotate in a counter clockwise direction indicated by thearrow A in FIG. 8 and that the rings generally. run synchronously.However, in order to bring the knives 136 and debarking blades 170 intocontact with the bole surface, it is necessary to alter thecircumferential position of the inner ring with respect to the outerring or vice versa. Assuming then that the outer and inner rings 103 and104 are rotating, relative rotation of inner ring 104 will pivot theleading end 124 of tool 102 about pivot 132 at the other end and therebydraw guide shoe 134, blades 170 and knife 136 toward the bole center.The tools are therefore closed by rotating theinner ring 104 in onedirection, relative to ring 103, and are open by rotation of ring 104 inthe other direction relative to ring 103. As with the earlierembodiment, a very precise, accurate and responsive control of guideshoe 134 and the associated tools is afforded by the rotary positioningof the rings 103 and 104 but in the present embodiment the control andaccuracy is greater than in the earlier inasmuch as the wider spacing ofthe pivot points in the tool allows a finer degree of adjustment.

While the rings 28 and 38 of the first embodiment were driven separatelyby their own motors, it should be noted that various forms ofdifferential means can be used to alter the rotational positioning ofone ring with respect to another. In the present embodiment, the meansto alter the rotational position of ring 104 with respect to outer ring103 is disclosed in FIGS. 6, l2 and 13. 1

As partially shown in FIG. 12 rings 103 and 104 are mounted for rotationin casing 110 by suitable bearings 172. Ring 103 has a circumferentialsprocket 174 secured thereto and inner ring 104 has a similar sprocket176. Sprocket 174 on ring 103 is rotated by drive means D whichtransmits rotary motion from any suitable power source through a drivesprocket 184, FIG. 13, and roller chain 180, FIG. 7, and which is alsotrained about a chain tensioner 182.

As shown in FIG. 13, drive means D also rotates sprocket 176 on ring 104by a second drive sprocket 178 but through a rotary actuator l 12. Inthe illustrated example this actuator comprises a rotary vane type whichprovides appropriate rotation to ring 104 with respect to ring 103effecting the opening and closing of the debranching and debarking tools102. The chain interconnecting sprockets 176 and 184 are also trainedabout tensioner 182.

Referring again to FIG. 13, drive sprocket 184 is directly connected toa coupling member 186 which in turn is secured suitably to the drivemeans D. A tubular coupling 188 interconnects the drive D with a splineshaft 190 of the actuator 112 while bearings 192 support the coupling188 in the structural wall 194 of the casing 110. Drive sprocket 178 isdirectly connected to coupling member 196, sub-plate 197 and actuator112, the assembly being supported by bearings 198 on tubular coupling188. The relative position of driving sprockets 178 and 184 is,therefore, determined by the vane position of rotary actuator 1 12 yetthe entire drive assembly can rotate freely in casing 110, the rotaryactuator 112 hydraulic connection being made by means of swivel joints114 to the power source. 7

Appropriate hydraulic control of the rotary actuator 112 governs theopening and closing of the tools 102 and the pressure of the guide shoes134 on the bole T as its diameter varies during processing through theapparatus 100.

When installed in a processing machine as shown in FIG. 1 theoperational sequence would-be as follows:

1. The apparatus 100, FIG. 6, is in rotary motion with tools 102, 1020and 102b orbiting in full open position.

2. A tree bole is fed butt end first into the apparatus to the depth ofdebarking blades 170 by the secondary feed system of arm 4 which alignsthe tree with the longitudinal axis extending through the apparatus 100,the feed system of arm 4 grasping the hole securely to prevent rotationby the action of the tools 102.

3. The rotary actuator 112 is operated to advance ring 103 with respectto ring 104 and thereby close the tools 102 onto the bole so that thedebarking blades 170 begin to remove the bark from the bole surface,throwing it outwardly due to the counter clockwise rotation.

4. The secondary feed system of arm 4 then feeds the bole into theapparatus until the primary feed rolls (FIGS. 3 and 4) grasp the boleand feed it through the apparatus, freeing the secondary feed.

5. The hole is drawn completely through the apparatus 100 until thetools 102 orbit to the limit of their closure.

6. The rotary actuator 112 which up to this time has maintained constantpressure at the interface between guide shoe 134 of tools 102 and thedebarked surface of the bole, is operated to open the tools 102 toreceive the next tree from the secondary feed system of arm 4 to repeatthe sequence.

Although this disclosure. refers to a specific type of delimbing knifeand debarking blade, it is well within the scope of the invention toutilize other types of debranching members on the tools 102 such asfly-cutters with an appropriate mechanical drive as known in the priorart, or to use only debarking members of conventional design when thetree boles being processed have previously been debranched, e.g., bymanual tools.

Additionally, this specification has referred to the apparatus operatingin a vertical orientation but it may also be used in static or mobileform in a substantially horizontal arrangement. Thedebranching-debarking apparatus should not be considered applicable onlyto the processing machine shown in FIG. 1, which is illustrated by wayof example.

I claim:

1. A rotary debarker comprising a. a support casing;

b. inner and outer rings coaxially mounted for rotation in said casingand defining a central opening therein to provide a path of travel for atree bole to be processed by said debarker;

c. power means for rotating the inner and outer rings in the samedirection;

d. a plurality of pivot pins secured to the surface of the outer ringand spaced evenly about said surface;

e. a plurality of guide pins secured to and spaced equally on thesurface of the inner ring;

f. a plurality of tool holders secured to said rings for rotationtherewith, each holder substantially spanning said rings in an arcuateform and having a first end pivotally secured to a pivot pin on theouter ring and a second end picotally secured to a guide pin on theinner ring; each said tool holder including a lower plate extendingbetween and connected to said guide and pivot pins and an upper platesecured at one end to the pivot pin on the outer ring, a portion of thelower plate being connected pivotally to the inner ring guide pin andbeing stepped to extend beneath the lower plate of an adjacent holder; aspacer pin adjacent the pivot pin and interconnecting the upper andlower plates of the holder; and debarking tools resiliently mounted onthe spacer pin and positioned to engage the surface of a severed tree inthe path of travel;

g. debarking tools on the first end of each holder extending inwardlytowards said path of travel to engage and process a tree passingtherethrough;

h. and a rotary actuator for altering the circumferential position ofone ring with respect to the other during rotation thereof whereby saidguide pins on the inner ring will advance or recede the second ends ofsaid holders and the tools thereon into or out of engagement with thesurface of said tree.

2. A debarker according to claim 1 including a delimbing knife on theother end of each upper plate, spaced above said debarking tools.

3. A debarker according to claim 1 including a guide surface on thelower plate of each tool holder adapted to ride the surface of saidsevered tree.

4. A debarker according to claim 1 wherein said debarker tools of eachholder comprises finger and knuckle members pivotally attached to thespacer pin; a connecting rod secured at one end to each finger andslidably engaging a knuckle member;

a debarking blade secured to each finger and having one end adapted toengage the surface of said tree; and spring means on said connecting rodurging the finger and blade away from the knuckle whereby the end of theblade will resiliently float upon the tree surface.

5. A debrancher according to claim 2 wherein the power means comprisesdriven sprockets on the inner v and outer rings, a motor and drivesprockets interconnected to the driven sprockets by roller chains, and arotary actuator intermediate the motor and one of the drive sprocketsfor altering its circumferential position with respect to that of theother drive sprocket whereby one of said rings will advance or retreatcircumferentially with respect to the other ring.

6. A rotary debarker comprising a pair of coaxially mounted ringsdefining a central opening therein to provide a path of travel for atree bole to be debarked; means for rotating said rings in the samedirection; a plurality of debarking tool holders each extending acrossthe path of travel in an arcuate line and bein pivotally mounted at oneend to one of the rmgs and a the other end to the other rings; portionsof said holders overlapping one another in an iris arrangement so thataltering the circumferential position of one ring with respect to theother will open or close the iris arrangement of the holders anddecrease or enlarge, respectively, the path of travel of the tree bole;and debarking tools mounted on each tool holder.

7. The debarker of claim 6 wherein each tool holder has a guide shoeintermediate its length and adjacent the central opening; said shoebeing adapted to slidably engage the surface of said tree bole.

UNKTEE STATES meme" @mm eeemmewe e? @ceeemfiew Patent No. 3,7 ,733 DatedDecember 5 19 7 Inventor(s) Bruce John MCCOll It is oertifie'd thaterror appears in the aboveide'ntified patent and that said LettersPatenpare hereby corrected as shown below;

Column '13, line 10, "picotally" should be ivot-all Signed and sealedthis 12th day" of June 1973'.

[SEAL] Attest': v

EDWARD M.FLETCHER,JR ROBERT GOTTSCHALK Attesting Officer I Commissionerof Patents RM P uscoMM-pc some-P69 U-S. GGVERNMENT PRIN ING OFFICE i9690-366-334.

1. A rotary debarker comprising a. a support casing; b. inner and outerrings coaxially mounted for rotation in said casing and defining acentral opening therein to provide a path of travel for a tree bole tobe processed by said debarker; c. power means for rotating the inner andouter rings in the same direction; d. a plurality of pivot pins securedto the surface of the outer ring and spaced evenly about said surface;e. a plurality of guide pins secured to and spaced equally on thesurface of the inner ring; f. a plurality of tool holders secured tosaid rings for rotation therewith, each holder substantially spanningsaid rings in an arcuate form and having a first end pivotally securedto a pivot pin on the outer ring and a second end picotally secured to aguide pin on the inner ring; each said tool holder including a lowerplate extending between and connected to said guide and pivot pins andan upper plate secured at one end to the pivot pin on the outer ring, aportion of the lower plate being connected pivotally to the inner ringguide pin and being stepped to extend beneath the lower plate of anadjacent holder; a spacer pin adjacent the pivot pin and interconnectingthe upper and lower plates of the holder; and debarking toolsresiliently mounted on the spacer pin and positioned to engage thesurface of a severed tree in the path of travel; g. debarking tools onthe first end of each holder extending inwardly towards said path oftravel to engage and process a tree passing therethrough; h. and arotary actuator for altering the circumferential position of one ringwith respect to the other during rotation thereof whereby said guidepins on the inner ring will advance or recede the second ends of saidholders and the tools thereon into or out of engagement with the surfaceof said tree.
 2. A debarker according to claim 1 including a delimbingknife on the other end of each upper plate, spaced above said debarkingtools.
 3. A debarker according to claim 1 including a guide surface onthe lower plate of each tool holder adapted to ride the surface of saidsevered tree.
 4. A debarker according to claim 1 wherein said debarkertools of each holder comprises finger and knuckle members pivotallyattached to the spacer pin; a connecting rod secured at one end to eachfinger and slidably engaging a knuckle member; a debarking blade securedto each finger and having one end adapted to engage the surface of saidtree; and spRing means on said connecting rod urging the finger andblade away from the knuckle whereby the end of the blade willresiliently float upon the tree surface.
 5. A debrancher according toclaim 2 wherein the power means comprises driven sprockets on the innerand outer rings, a motor and drive sprockets interconnected to thedriven sprockets by roller chains, and a rotary actuator intermediatethe motor and one of the drive sprockets for altering itscircumferential position with respect to that of the other drivesprocket whereby one of said rings will advance or retreatcircumferentially with respect to the other ring.
 6. A rotary debarkercomprising a pair of coaxially mounted rings defining a central openingtherein to provide a path of travel for a tree bole to be debarked;means for rotating said rings in the same direction; a plurality ofdebarking tool holders each extending across the path of travel in anarcuate line and being pivotally mounted at one end to one of the ringsand at the other end to the other rings; portions of said holdersoverlapping one another in an iris arrangement so that altering thecircumferential position of one ring with respect to the other will openor close the iris arrangement of the holders and decrease or enlarge,respectively, the path of travel of the tree bole; and debarking toolsmounted on each tool holder.
 7. The debarker of claim 6 wherein eachtool holder has a guide shoe intermediate its length and adjacent thecentral opening; said shoe being adapted to slidably engage the surfaceof said tree bole.